The present invention relates to a lubricating system for rock drill machines driven by pressurized fluid, comprising a lubricant reservoir, passages for coducting the lubricant to the lubrication points and means for feeding lubricant into said passages.
Oil mist lubrication is a typical feature in the design of compressed air driven rock drills. In that case the compressed air constituting the driving power is either conducted through mist generators or the lubricant is dosed into the compressed air system. The greatest drawback of this system of the prior art is that the compressed air, and the lubricant along with it, finds the path of least resistance through the drill machine, whereby the assurance of lubrication of the proper points is not controllable, and such large quantities of lubricant have to be introduced into the operating air that even the points most difficult to lubricate will positively receive enough lubricant. This makes the lubricant content of the operating air so high that the drill machine is not able to utilize the whole lubricant, the greater portion thereof escaping together with the exhaust air from the drill and causing environment pollution. It is also obvious that an unnecessary amount of lubricant is consumed, which involves high costs.
Concerning the lubrication of a hydraulic rock drill, in which the actuating fluid is oil, the problem is that the oil which is appropriate to power the drill is not particularly suitable for use as lubricating oil.